Carriage return mechanism for automatic typewriters



Dec. 26, 1939. s. w. CARLSON 2,184,278

CARRIAGE RETURN MECHANISM FOR AUTOMATIC TYPEWRITERS Filed Jan. 29, 1936 3 Sheets-Sheet 1 fi ql 39 56 38 6 E, REF may 2 y a M L'IIIIII-A l i 5 e e I ."Ufl ..U W? 9 I 5 a2 A TIA l 19 WW l-- 28 at: INVENTOR De; 26,' 1939. s. w. CARLSON CARRIAGE RETURN MECHANISM FOR AUTOMATIC 'TYPEWRITERS s Sheigs-Sheet 2 Filed Jan. 29, 1936 mm kw W m a vb mm ll I lll| P QM N02 Dec. 26, 1939. s. w. CARLSON CARRIAGE RETURN mncnmxsu on AUTOMATIC TYPEWRITERS 3 Shets-Sheet 5 Filed Jan. 29, 1936 INVENTOR Patented Dec. 26, 1939 CARRIAGE RETURN MECHANISM FOR AUTOMATIC TYPEWRITERS George W. Carlson, Pittsburgh, Pa., assignor to Robert H. McClintic, Pittsburgh, Pa.

Application January 29, 1936, Serial No. 61,355 10 Claims. 01. 197-20) This invention relates to typewriters of the character wherein a record-controlled mechanism is provided for operating the keys of a typewriter and is for a mechanism for returning the carriage of the typewriter to its starting position.

Automatic typewriters generally comprise a standard typewriting machine which is mounted on and connected with a mechanical unit, this unit being controlled by a record sheet. Such mechanisms are generally pneumatically operated. In the operation of any standard typewriter, the carriage moves across the typewriter with the operation of the keys. When a complete line has been written or the marginal stop has been reached, the carriage has to be returned to its starting position and the platen has to be rotated to advance the paper. The movement of the carriage under the operation of the keys is from right to left, and in returning the carriage it is moved from left to right. Typewriters are usually provided with a single lever which, when pushed to the right, serves to transmit motion to the carriage to return it and which simultaneously rotates the platen or roller a predetermined amount.

In automatic typewriters, this operation of the carriage, of course, has to be effected automatically. According to the present invention, there is provided a simple and unique carriage return mechanism which is positive in its action, relatively cheap to manufacture and install, and which does not require the use of excessively large pneumatics for operating it. The invention further provides a carriage return mechanism which is controlled by the record sheet, but which may also be operated through a push button action so that when the typewriter is being operated manually the operator has only to push a button to effect the carriage return instead of reaching up to the carriage and manually pushing the carriage to its starting position.

The invention may be readily understood by reference to the accompanying drawings, in which:

Figure 1 is a front elevation of an automatic typewriter unit to which the present invention is applied;

Figure 2 is an enlarged transverse section through the reel mechanism and clutch;

Figure 3 is a schematic view showing the carriage return mechanism and fragments of the various parts entering into the combination, some of the parts being shown in plan and .some

in elevation, the drawings illustrating the pneumatic circuits and arrangement of parts, the parts not being shown, however, in their correct location;

Figure 4 is a top plan view showing a portion of the ordinary typewriter carriage and operating lever and a part of the return mechanism;

Figure 5 is a detail view showing the spring arrangement at the center of the reel;

Figure 6 is a detail sectional view through the manually operated valve or push button;

Figure 7 shows a side elevation of a portion of the drive mechanism; and

Figure 8 is a schematic view somewhat similar to Figure 3, showing an arrangement wherein the clutch is operated electrically instead of pneumatically.

In the drawings, I have illustrated certain parts of 'a mechanical typewriter operating mechanism which are shown more fully and in greater detail in my copending applications, Serial Nos. 68,068 and 68,071, filed March 10; 1936, and 61,356, filed January 29, 1936, and in the present application have only shown such portions of said mechanisms as are necessary to illustrate the present invention. It will be understood that the present invention is not restricted to any particular type of mechanically operated typewriter, and may be adapted for use with mechanisms other than the particular pneumatic action shown.

Referring first to Figures 1 to '7, 2 designates the supporting frame for a typewriter operating mechanism, and 8 designates a typewriter of any known or'preferred construction. This typewriter is provided with the usual carriage 4, the carriage having a platen roll 5 and having an operating lever B through which the carriage is moved to its starting position and through the operation of which the roll is simultaneously rotated a predetermined distance. The construction of the typewriter or of the carriage or of the lever 6 forms no part of the present invention per se, and such constructions are so well known in the art as to require no detailed description. When the lever 6 is pressed toward the right as viewed in Figures 1 and 4, it pivots about a point I, operating a pawl 8 to advance ratchet wheel 8 on the end ofthe roller 5. At the same time, the carriage, by reason of this pressure, is caused to roll toward the right. The automatic typewriter mechanism includes adriving motor l0 (see Figure 7).. This motor is connected by a belt II to a pulley l2. The pulley I2 is provided with another pulley l3 at its hub which is connected by a belt i 4 to a third.puiley l5. The pulley I5 is on the end of a vacuum pump operating shaft which pump is generally indicated as l1 in Figure 1, the details of which are not shown, the pump per se forming no part of the present invention.

The pulley I2 is mounted as shown in Figures 2 and 3, being supported on a bearing IS on a hollow stud l8, which stud passes through an opening in the frame 2 and is held in place by a nut l9. The pulley l2 has a flat outer face |2a to which is cemented an annulus |2b of friction material as, for instance, cork. Screwed into the end of the stud I8 is a sleeve-like extension 20. This sleeve is provided with a bearing or bushing 2| around which is a flanged sleeve 22. Carried on the flanged sleeve 22 is a reel 23, this reel having a recessed hub 24 at one side thereof and having a flange portion 25 which overlies the annulus |2b of friction ma-' terial. Within the recess in the hub 24 of the reel is a spiral spring 26 (see Figure 5), one end of which is connected to the hub of the reel and one end of which is connected as indicated at 21 to the stationary extension 20 of the stud 8. At 28 is a thrust bearing which is confined between the sleeve 22 and a cap-like nut 29, this nut 29 being secured to the end of a rod 30. The rod 30 passes through theframe of the machine as illustrated in Figure 3 to the opposite side thereof. Its opposite end passes through an opening in an extension 3| on a pneumatic 32. A nut 33 on the end of the rod 30 limits the relative movement between the rod 30 and the extension' 3| on the pneumatic. The pneumatic is of a type commonly employed in pneumatic actions of the player piano type. When the pneumatic 32 collapses, i. e., the outer part thereof moves to the right as viewed in Figure 3, the operating extension 3| moves to the left, there being a fulcrum point built into the hinge of the pneumatic as indicated at 32'. Movement of the extension 3| to the left exerts a pull on the rod 30. This pull is transmitted to the rod 39 whereupon the nut 29 applies pressure to the thrust bearing 28 by means of which the reel is moved to the left as viewed in Figure 2, bringing the friction surface 25 of the reel into contact with the friction surface |2b of the continuously revolving pulley i2.

The pneumatic 32 is opposed by a compression spring 34 confined between the frame 2 of the machine and a thrust collar 35 on the shaft 30. Attached to the reel is a flexible tape 36. This tape passes up through a fixed guide 31 at one side of theframe 2 (see Figure 1). At the top of the guide 31 is a pulley 38 over which the tape passes, the tape passing across the top of the typewriter and being secured as indicated at 39 to the carriage-operating lever 6. In the operation of the machine, when the pneumatic 32 operates to pull the rod 30 to the left, thereby bringing the reel into driving contact with the pulley 2, the reel is caused to rotate in a clockwise direction, winding the tape 36 up on the reel. The winding up of the tape exerts a pull on the lever 6 and this pull continues until the carriage has been moved toward the right to the limit of its movement, after which slippage will occur between the flange 25 and the friction surface |2b of the pulley 2 until the pull on the rod 30 is released. When the pull on the rod 30 is released, spring 34 urges the rod 30 toward the right as viewed in Figures 2 and 3, allowing the friction flange 25 of the reel to disengage from the friction surface on the pulley. Therefore, while the machine is operating, i. e., while the motor I0 is running, the carriage may be returned to its starting position and the roller turned the desired distancewith each operation of the carriage merely by effecting operation of the pneumatic 32. As previously indicated, when the tape is wound up as far as it' will go, the slippage will occur between the reel and the pulley |2 until the pressure exerted by the pneumatic 32 is relieved.

With this arrangement it will be noted that the pneumatic operates merely to move a clutch, while the actual power for returning the carriage to its starting position is provided by the motor in.

With the present invention, the operation of the pneumatic may be eifected either by the record sheet moving over the tracker bar of the mechanism or by the operation of a manual valve, preferably of the push button type. This mechanism for operating the pneumatic will next be described.

Leading from the pneumatic 32 is a tube connection 40 to which is attached a tube 4| leading to a main control valve casing 42. Adjacent the connection 40 is a passageway 43 opening to atmosphere, which passageway is controlled by an adjusting screw or valve 44.

Within the casing 42 is a chamber 45, which chamber communicates through a passage (not shown) to a pipe 46 leading to the vacuum pump i1. At the bottom of the chamber is a thin leather diaphragm 41, which diaphragm is known in the pneumatic art as a pouch".

Above the pouch 41 is a valve chamber 43 in which is a valve 49, the valve 49 being of a type common in the pneumatic art and having a depending projection 50 terminating above the pouch 41. The depending portion 50 of the valve loosely pases through a port 5| by means of which a fluid passage is provided from the valve chamber 48 to the pouch chamber 45. Above the valve 49 is a port 52 which through a passageway 52a leads to the atmosphere. Below the pouch 41 is a passageway 53 which divides, one branch of which enters a chamber 54 in the casing 42 and the other branch, 55, leads to a manually operable valve of the push button type, 56. There is a passageway 51 in the valve casing or block 42 which communicates with a tube 58 leading to an opening 59 in a tracker bar 60. In Figure 3, a record sheet A is indicated over the tracker bar. The record sheet A is moved during the operation of the machine over the tracker bar in a manner well understood by those skilled in the art. One form of driving mechanism for records of this type is illustrated in my copending application, Serial No. 68,071, filed March 10, 1936. In the chamber 54 is a thin leather flap 6|. Below this flap is a pouch 52. A passage 63 leads to the underside of the pouch 52-. The entrance of atmospheric air through the passage 83 is controlled by a valve 64, which valve controls a port 65 leading to atmosphere.

Themanually operable valve 56 is of any known or preferred construction. In Figure 6, this valve is illustrated as comprising a block 56a having a tubeconnection 56b to which the tube is connected. Within the block 56a is a passage 58c leading to a port 56d. Secured to the bottom of the block is a spring metal flap 566 which may have a leather sealing disc 56f thereon. The free end of this flap extends under a push button 56g, which button is retained in the block 56.

When the button 559 is pushed down, the spring flap 55e is moved down so as to open the port 55d to atmosphere. When pressure is removed from the push button 55g, the spring flap 55c through its own resilience returns to a position where the port 5503 is closed.

In cutting the record A the record perforating device is operated to form a perforation a in the record at such points as it is necessary for a carriage return operation to be effected. The opening a is preferably a long opening or the equivalent of a long opening, such as several perforations so close together as to, in effect, form a continuous opening. When the record A is moving over the tracker bar in the direction of the arrow shown in Figure 3, the parts will normally be in the position illustrated in this figure. When the perforation a moves over the tracker bar opening 59, atmospheric air will enter the tube 58 under the chamber 54 and pass from the chamber 54 through the passage 53 to the under side of the pouch 4'1. Since there is a partial vacuum in the chamber 45 above the pouch, the admission of atmospheric air tothe under side of the pouch will cause the pouch to be lifted, lifting the valve 49 to close the port 52. At the same time, a suction passage then exists from the pneumatic 32 through the tube 4| down the port 5| into the chamber 45. The suction on the pneumatic 32. causes it to collapse, moving the operating extension 3| thereof to the left as viewed in Figure 3, and operating the clutch to cause the reel to operate in the manner hereinbefore described. The slot at in the record sheet A is of such dimension as to cause the pneumatic 32 to remain collapsed long enough to cause the reel to wind up enough tape to return the carriage. As soon as the opening a in the record A clears the port 59, the atmospheric air in the passage 53 and associated passageways will be exhausted through the restricted orifice or bleeder cup 41a, which bleeder cup establishes a restricted communication between opposite sides of the pouch. When this occurs, the pouch 41 drops to the position shown in Figure 3 and the valve 49 drops down, closing the suction through the port 5! and allowing atmospheric air to enter the passage 52a and the port 52 and pass around the valve 49 into the tube 4| and the pneumatic 32, thereby allowing the penumatic to expand to its normal position, permitting the reel clutch to release.

The carriage may be manually returned to a starting position at any time by operation of the push button 559 forming part of the manual valve 55. .This valve 55 is preferably supported on the level of the keyboard of the typewriter and to one side of the typewriter as shown in Figure 1, so that the operator of the typewriter, can easily push this button while operating the typewriter. When the button 55g is depressed to open the port 55d in the manner hereinbefore described, the air entering from the atmosphere is led through the tube 55 to the under side of the pouch 41, operating the valve 49 in the same way that this valve is operated by air entering through the tracker bar opening 59. When pressure is relieved from the push button 55gand port 55a, is closed, the parts immediately When the record sheet A is rewinding, it ,is,.o

course,- desirable that the carriage return mechanism be not operated. The valve 54 is-operated by means not shown and forming no part of the present invention, to admit atmospheric air return to the position shown in Figure 3. v w

through passage 55 and passage 54 to the under side of the pouch 52. The chamber 54 is also connected to the vacuum line 45, and when atmospheric air is admitted to the under side of the pouch 52 the pouch 52 is lifted, pushing the flap 5| up against the bottom of the passageways 51 and 53 so that air which enters the opening 59 in the tracker bar during the rewindimg operation cannot pass from the passage 51 into the passage 53 to operate the pouch 41. At the end of the record rewinding period the valve 54 is closed, allowing the parts to return to the normal position shown in Figure 3, so that with the next forward operation of the record, the carriage return mechanism will operate. The operation of the valve 54 is controlled by a rewinding opening in the record A, the circuit for operating the valve 54 constituting no part of the present invention and is more fully disclosed and claimed in my copending application, Serial No. 68,068, filed March 10, 1936.

The purpose of the spiral clock spring inside the hub portion 23 of the reel is for maintaining a slight tension on the tape 35 at all timeswhen the reel. is not in frictional engagement with the driving pulley, thus preventing the tape from unwinding from the reel when the clutch is disengaged or when the machine is not operating. .If the spring 25 were not provided, the tape 36 would tend to become unreeled and possibly fouled around the reel in such manner that the mechanism could not operate. Thedisposition of thespring 25issuchthat as the carriage 5 moves toward the left as viewed in Figure 4, unwinding the tape 35 from the reel tends to wind up or tighten the spring 25. Since the tape cannot unwind from the reel without winding up the spring 25, it is obvious that it will be kept always under tension.

By adjusting the screw 44 the effect of vacuumapplied to the pneumatic 32 can be adjusted to thereby vary the pressure applied by the pneumatic 32 through the pull rod to the clutch. If the clutch tends to slip during the normal operation of the machine, thescrew 44 is turned to more completely close the relief passageway to the atmosphere so that a more effective vacuum or suction is applied to the pneumatic 32.

The entire mechanism issimple, cheap to construct and install and is positive in its operation. As previously stated, the power for the carriage return is supplied by the motor III while the vacuum pump has only the relatively small pneumatic 32 to operate. Thus, it is much more simple and effective than devices of the type at present in use wherein a single large pneumatic is attached to the tape in place of a reel. Since there is very little wear in the clutch, the friction surface of the clutch will last for a long period of time without renewal. The mechanism does not require that any valves or other attachments, other than the tape 35 be actually applied to the typewriter itself. Even when the typewriter is being operated as an ordinary typewriter but with the motor l0 running, it is of considerable convenience for the operator to effect the return of the carriage and the advancement of the roller 5 by merely pushing a key or button 559 in place of reachin up to the top of the typewriter in the customary manner. 7 V I In place of an entire pneumatic system of oper-, ation,the invention contemplates that theoper ation of the clutch can be effected through electrical means. Figure 8 indicates, more or less schematically one way in which such electrical 25 operation can be effected. In this figure, 2 designates the supporting frame as previously described, and 80 designates the clutch operating rod similar to the rod 30 previously described.

,Iihe clutch and reel arrangement is similar to that previously described and has accordingly not been shown. Instead of the pneumatic 32, I have shown an electromagnet 10. An armature II is carried on a pivoted lever 12, this lever having a pivoted support at 13, and having its other end 1 pivotally connected to the pull rod 30. 42' designates a pneumatic valve casing corresponding to the casing 42 previously described. In place of a' valve member 49, however, the casing 421' is provided wth a suction chamber 15 leading to the pneumatic pump through a passage (not shown). In the bottom of this suction chamber is'j'a well 16 over which is a pouch TI correspondin; all respects to the pouch 41. A passage Il corresponding to the passage 53 leads to the under side of the pouch TI. The other passages connections are similar to those previously described and have therefore not been shown in Fig. 7. The pouch 11 carries a disc member I9 on the top of which is a metallic or carbon disc 80. Passing through the top of the valve casing above the pouch are two electric contacts 8| and 82, the passage around these contacts, of course, being tight to prevent leakage of atmospheric air. A bleeder cup is indicated at 11a.

.When atmospheric air enters the passage I8 either by reason of the record traveiingover the tracker bar or by reason of the operation of the manual valve as previously described, the pouch 'lLis lifted, bringing the contact disc 80 into engagement "with the fixed contacts M and 82. Contact 82 is provided with a wire 83 leading tofa source of current (not shown). Contact 8| leads through wire 84 to one: side of the electromagnet III, the electromagnet 10 being connected through a wire 85 to the other side of an electric circuit. When the disc 80 engages the two contacts BI and 82, a circuit is completed across the gap between those two contacts to energize the electromagnet 10, thereby attracting the armatu're H to it and thus exert a pull on the rod 30 to operate the clutch. When the pouch 11 drops down to the normal position shown, the circuit through the electromagnet is broken and the parts are restored to the normal position. Thus it' will be seen that the invention is equally adapted to operation of the clutch through electrical means.

While I have shown and described certain preferred embodiments of my invention, it will be understood. that various changes and modifications are contemplated within the scope of the following claims.

Lclaim:

I, An apparatus of the class described comprisingia reel, a continuously driven r ember, a clutch by means of which motion is transmitted from the driven member to the reel and operable into and out of reel-operating position, and record-controlled means for operating the clutch to both operate and release the clutch.

2. A mechanism of the classdescribed comprising a clutch having one member which is continuously driven and which carries a friction surface on one face thereof, a second member movable axially with respect to the first into and out of driving relation therewith, said second member having a reel associated therewith, and a recordcontrolled means for moving said second member both into and out of driving relation with the first.

3. A carriage returnmechanism of the class described comprising a motor driven member, a rotary clutch member movable between two positions in one of which it is rotated by the driven member, record-controlled means for effecting the operation of the clutch member to both positions, and means operated by the rotary clutch member for transmitting motion to a typewriter carriage.

4. A carriage return mechanism of the class described comprising a motor driven member, a rotary clutch member, means for operating the clutch member to bring said members into driving relation and releasing them, a single pneumatic action for controlling the operation of said last named means, and means for transmitting motion from the rotary clutch member to a carriage,

5. In a mechanism of the class described, a motor driven disc member having a friction surface on one face thereof and a fixed support for said member, a second member having a driving face for cooperation with said friction face of the first'member mounted for movement in an axial direction with respect to said first member, a thrust member and pull rod through which axial movement of said second member is effected in one direction to hold said second member in driving relation with the first, and record-controlled means for operating the pull rod to both operate and release the clutch.

6. A carriage return mechanism for automatically operated typewriters, comprising a reel, a friction clutch for driving the reel, said clutch being shiftable into and out of reel-operating position, a pneumatic for holding the clutch in reel-driving position, means acting in opposition to said pneumatic for releasing the clutch, and an adjustable suction-controlling valve for the pneumatic.

7. A carriage return mechanism comprising a friction clutch, a reel driven through said clutch, said clutch being shiftable into and out of reel-- operating position, a pneumatic for holding the clutch in reel-driving position, means acting in opposition to saidpneumatic for releasing the clutch, an exhaust line, a record-controlled tracker bar havingan opening therein for controlling said, pneumatic, a pneumatic valve connected with said tracker bar opening and for connecting said pneumatic with the exhaust line when the pneumatic is to be operated, and an adjustable bleed valve between the pneumatic and pneumatic valve for regulating the force with which the pneumatic operates the clutch.

8. A carriage return mechanism for automatically operated typewriters, comprising a pulley having a web portion, a disc member adjacent the pulley having a reel-thereon and movable axially into and out of frictional engagement with the face of the web of the pulley, a supporting shaft or. which the pulley and disc membertare mounted for free rotation, a thrust rod passing axially through the shaft and having a thrust member at one end adjacent the reel for pressing the disc member against the web of the pulley, and means for operating the thrust rod.

9. A carriage return mechanism for automatic typewriters, comprising a reel, a driving member,

-a clutch interposed between the driven member and the reel for driving the reel, means for operating the clutch to hold it in reel-driving position, a spring acting in opposition to said means, and pneumatic means for controlling the said clutchoperating means including-a pneumatic valve connected with emotion line, a tracker bar having a record-controlled opening leading to the valve, the

are-rm 5 friction clutch for driving the reel, said clutch being shiftable into and out of reel-operating position, a pneumatic for holding the clutch in reeldriving position, means acting in opposition to said pneumatic for releasing the clutch, and adjustable means for controlling the pressure 6 exerted by said pneumatic.

GEORGE w. CARLSON. 

